package com.ohuang.filemanager.util;

import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.Build;
import android.os.Environment;
import android.os.Looper;
import android.util.Log;
import android.widget.Toast;

import java.io.File;
import java.io.FileOutputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.lang.Thread.UncaughtExceptionHandler;
import java.lang.reflect.Field;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

/**
 * UncaughtException处理类,当程序发生Uncaught异常的时候,有该类来接管程序,并记录发送错误报告.
 * Created by YIYI on 2017/10/10.
 */

public class CrashHandler implements UncaughtExceptionHandler {
    public static final String TAG = "CrashHandler";
    //系统默认的UncaughtException处理类
    private UncaughtExceptionHandler mDefaultHandler;
    //CrashHandler实例
    private static CrashHandler INSTANCE = new CrashHandler();
    //程序的Context对象
    private Context mContext;
    //用来存储设备信息和异常信息
    private Map<String, String> infos = new HashMap<String, String>();

    //用于格式化日期,作为日志文件名的一部分
    private DateFormat formatter = new SimpleDateFormat("yyyyMMddHHmmss");

    //保证只有一个CrashHandler实例
    private CrashHandler() {
        //构造函数
    }

    //获取CrashHandler实例,单例模式
    public static CrashHandler getInstance(){
        return INSTANCE;
    }

    /**
     *  初始化
     *  @param context
     */
    public void init(Context context){
        mContext = context;
        //获取系统默认的UncaughtException处理器
        mDefaultHandler = Thread.getDefaultUncaughtExceptionHandler();
        //设置该CrashHandler为程序的默认处理器
        Thread.setDefaultUncaughtExceptionHandler(this);
    }
    /**
     *  当UncaughtException发生时会转入该函数来处理
     */
    @Override
    public void uncaughtException(Thread thread, Throwable ex){
        if(!handleException(ex) && mDefaultHandler != null)
        {
            //如果用户没有处理则让系统默认的异常处理器来处理
            mDefaultHandler.uncaughtException(thread, ex);
        }
        else{
            try{
                Thread.sleep(3000);
            }catch(InterruptedException e){
                Log.e(TAG, "error : ", e);
            }
            //退出程序
            android.os.Process.killProcess(android.os.Process.myPid());
            System.exit(1);
        }
    }

    /**
     * 自定义错误处理,收集错误信息 发送错误报告等操作均在此完成.
     *
     * @param ex
     * @return true:如果处理了该异常信息;否则返回false.
     */
    private boolean handleException(Throwable ex) {
        if (ex == null)
            return false;

        //使用Toast来显示异常信息
        new Thread(){
            @Override
            public void run(){
                Looper.prepare();
                Toast.makeText(mContext, "很抱歉,应用出现异常,即将退出！", Toast.LENGTH_LONG).show();
                Looper.loop();
            }
        }.start();
        //收集设备参数信息
        collectDeviceInfo(mContext);
        //保存日志文件
        saveCrashInfo2File(ex);
        return true;
    }

    /**
     * 收集设备参数信息
     * @param ctx
     */
    public void collectDeviceInfo(Context ctx){
        try{
            PackageManager pm = ctx.getPackageManager();
            PackageInfo pi = pm.getPackageInfo(ctx.getPackageName(), PackageManager.GET_ACTIVITIES);
            if(pi != null) {
                String versionName = pi.versionName == null ? "null" : pi.versionName;
                String versionCode = pi.versionCode + "";
                infos.put("versionName", versionName);
                infos.put("versionCode", versionCode);
            }
        }catch(NameNotFoundException e){
            Log.e(TAG, "an error occured when collect package info", e);
        }
        Field[] fields = Build.class.getDeclaredFields();
        for (Field field : fields){
            try{
                field.setAccessible(true);
                infos.put(field.getName(), field.get(null).toString());
                Log.d(TAG, field.getName() + " : " + field.get(null));
            }catch(Exception e){
                Log.e(TAG, "an error occured when collect crash info", e);
            }
        }
    }

    /**
     * 保存错误信息到文件中
     * @param ex
     * @return 返回文件名称,便于将文件传送到服务器
     */
    private String saveCrashInfo2File(Throwable ex){
        StringBuffer sBuffer = new StringBuffer();
        for(Map.Entry<String, String> entry : infos.entrySet()){
            String key = entry.getKey();
            String value = entry.getValue();
            sBuffer.append(key + "=" + value + "\n");
        }

        Writer writer = new StringWriter();
        PrintWriter printWriter = new PrintWriter(writer);
        ex.printStackTrace(printWriter);
        Throwable cause = ex.getCause();
        while(cause != null){
            cause.printStackTrace(printWriter);
            cause = cause.getCause();
        }
        printWriter.close();
        String result = writer.toString();
        sBuffer.append(result);

        String fileName = null;
        try{
            long timestamp = System.currentTimeMillis();
            String currTime = formatter.format(new Date());
            fileName = "crash-" + currTime + "-" + timestamp + ".log";
            if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
                String path = mContext.getFilesDir().getAbsolutePath();
                File dir = new File(path);
                if(!dir.exists()){
                    dir.mkdirs();
                }

                FileOutputStream foStream = new FileOutputStream(path + fileName);
                foStream.write(sBuffer.toString().getBytes());
                foStream.close();
            }
        }catch(Exception e){
            Log.e(TAG, "an error occured while writing file...", e);
        }
        return fileName;
    }
}
